There are a lot of prewar blues guitarists out there to investigate, and not all of them are guaranteed to ring your chimes. Blues was, and is, an incredibly varied music, and even within a category like "country blues" you'll find stuff you dig and stuff you don't get. As you follow the trail of liner notes, friends' recommendations and promises of various artists' "genius," take the time to listen for yourself and see what honestly resonates with you, what genuinely tickles your fancy.